PROJECT SUMMARY/ABSTRACT We propose mHealth Messaging to Motivate Quitline Use and Quitting (M2Q2), a collaborative research project for a mobile health intervention designed to motivate smoking cessation and encourage access to counseling, and targeted to men and women smokers in Vietnam's Red River Delta region, a largely rural area. Cigarette smoking is the number one preventable cause of morbidity and mortality, and tobacco-related deaths are predicted to increase worldwide, particularly in low and middle-income countries. In Vietnam, currently over 50% of men (and 2% of women) smoke combustible cigarette products. Per the World Health Organization (WHO) Framework Convention for Tobacco Control, Vietnam has implemented several initiatives to support tobacco cessation, including the initiation of quitlines. However, these quitlines are underused; over the past 6 months, a quitline in North Vietnam was called only about 25 times per day, a fraction of the smokers in the region. Our goal in this proposal is to increase use of the quitline, increasing access to counseling services, nicotine replacement therapy, with the goal of promoting cessation among current tobacco users. In prior work, we have leveraged automated messaging technology to engage patients in public health smoking cessation interventions, using email and text messages to encourage patients to seek counseling services, and to send motivational messages to smokers encouraging them to quit. Based on this work, we have demonstrated that clinics are willing to refer patients to a messaging system, as it requires minimal time within the busy clinical encounter. Further, we have found that motivational messages written by smokers for other smokers out-perform messages purely written by experts in tobacco control. Combining the strength of automated mobile health with cultural adaptations written by Vietnamese smokers for other Vietnamese smokers, and the counseling services of quitlines, we propose the following Specific Aims: Aim 1: In collaboration with the Institute of Population, Health, and Development (PHAD) in Hanoi Vietnam, we will adapt our current, effective texting system to Vietnam. The texting system will: 1) Motivate smokers to quit smoking, using tailored messages adapted to be culturally relevant, and 2) Encourage smokers to accept counseling services from the quitline, and take advantage of no-cost NRT that will be provided by the quitline to those willing to quit. Aim 2: Engage with the Bach Mai quitline, providing additional training in tobacco cessation counseling for those ready to quit, and motivational interventions for those not yet ready to quit. Aim 3: In a randomized trial (N = 600 men and women smokers in the Red River Delta), evaluate the impact of the texting system on access to the quitline, use of nicotine replacement therapy, increase in self-efficacy, and six-month biochemically verified smoking cessation. Our primary hypothesis is that smokers in the M2Q2 intervention will have higher rates of smoking cessation, compared with the comparison group. This application builds on our previous collaborations with the Vietnamese Ministry of Health and with PHAD in Hanoi, Vietnam. Over the past five years together, we have conducted both epidemiologic and intervention work, including successful conduct of a cluster-randomized trial in district medical clinics in Hung Yen with NIH funding.